Background: To improve participation rate, accuracy and respondents' compliance, it is important to know the respondents' viewpoint.
Objective: To evaluate respondents' preferences and perception about the EPIC-Soft (the software developed to conduct 24-h dietary recalls (24-HDRs) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study) 24-HDR interviews and to compare these preferences and perception between population groups (for example, between genders).
Design: Data were collected in Belgium, Czech Republic, France, the Netherlands and Norway in 2007. Two 24-HDRs (face-to-face and telephone administered) were conducted using EPIC-Soft. An evaluation questionnaire on different study aspects was completed by the respondents.
Setting: Data were collected in the European Food Consumption Validation Study.
Subjects: A convenience sample of 600 apparently healthy men and women, 45-65 years old and including all educational levels, were recruited (120 subjects per country). Differences among population groups were compared by means of the χ (2)-test.
Results: A total of 585 respondents completed the evaluation questionnaire. In all, 88% experienced problems only to a low degree when answering face-to-face and telephone-administered 24-HDR using EPIC-Soft. A total of 15% would have preferred help of another person during the face-to-face interview in the study center (mainly men: P < 0.001). Significantly, more subjects in the Netherlands and in Norway preferred two telephone (instead of face-to-face) interviews compared with the other countries (P<0.001).
Conclusion: Most subjects only experienced problems to a low degree during the EPIC-Soft interviews. Differences in preferences and capabilities to answer the EPIC-Soft interviews were identified between population groups (for example, gender differences). Therefore, the methods and the design to be used in a survey should be adapted according to the study population, so as to optimize response rate and compliance.